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Astronomers report finding a dead white dwarf star, with no detectable surrounding disk, producing a powerful shock wave that has apparently persisted for at least 1,000 years — a phenomenon researchers say 'shouldn't exist.' The star's magnetic field may partly explain the effect, but scientists believe an unexplained additional 'mystery engine' could be at work. The discovery challenges existing models of stellar remnants and could prompt new theoretical work to explain how such long-lived shock waves can form and persist around compact dead stars.